Coal-dust feeder and mixer



Patented Jan. 1,Y 1929.

'A s'fs i UNITE Y wILLAM-M. BARKER, or? CANTON, omo.y

A i 1,697,585 l l,

, vc'zoAL-nusr FEEDERAND MIXER.

Application meer neember 1o, 192e. l serial No. 154,o2."

l"complete combustion` 'and for Vfeeding this,

Y properly proportioned combustible mixturey f into aA combustion chamber or firebox.

. Up to the present "time, a numberof dev` vlces have been used to feed coal dust or powdered oo'al from the usualstorage orv Y feed bins, to the combustion chamber.' Innulnerabley mechanismsv including l. feed screws, air nozzles, or 1n]ectorshave'been mixing land feedingl into the `combustion Chambers, Y 4 Y Y I The variousv arrangements of these feeding:

and mixing mechanisms with the'r bins and `vfrebo2`zes'become in some-.instances *very elaborate and'complicated, but in `spite 0f this, their continuousactiony has beennunce'rtain.v t l Whatever:

lyconstant for any given frate of feeding of a combustible lmixture into'the fire-box.

The' arrangements including feeding. mech-' anisms such as Vvfeed s'creivs,V air nozzles,

or injectors," hav'ebeen4 uncertain in theirV action because the 4coal 'dust ror powdered f P cOal, being semi-fluid, has beenfound to' be Y inability to secure a' continuouslyl constant inoludingair nozzles Vor injectors. c -JIt is obvious that an inability tof control n fthe rate of feed ofthe coal 'dustinto *thea'irv '1stream, renders it impossible tof e'e'dinto V the"combustion chamber, regardlessl of what f 'i means may begemployed to mix the -airffand' rateof feeding ofthe coal dust into the air stream hasbeen encountered lwith devices 'coal dustya continuously constant 'combust the method used "to morek thoroughly mix "the :quantity ;o'f ooalfdustj delivered intowthe air; stream by the feed` screws, nozzles or injectors, it is first;ofall" necessary that this quantity of fuel delivered into the air stream shall remain continuous-f Shared, ingwhieha: l

proportionsof coaldust fand air. i 55 It 1sof course vwell known in 'theart of fuel combustion that'most efficient combustion `of any given" powderedor gaseous vfuel obtained'by combining the vfuel and air in proportionsdetermined bythe Acherni'c'ah analysis of ythe particular fuel, and which proportions may loel predetermined' for any given fuel, and kby intimately mixinglthese proportions 'of fuel and air with eachother. yv`For any givenvfuel the proper proportions 65 of fuel and' air for the'combustible miture devised to deliver'the coal dust fromvthe bins through orifices into ducts where an air stream picks up the coal dust for further remains constant and unvarying regardless of the v rate of feedingthe mixtureinto the combustion chamber or fire-box. l

Accordingly the objects of my `I )resent iin-fio y provements are to provide a new andsimple method and apparatusforcontinuously and automatically mixing any desired pulverize'd `or gaseous fuel, such. as coal dustfwith the proper'quantity ofa'ir necessary for comin-5:75` uously vconstantandd complete combustion, Y i the apparatus simultaneously and continuyously delivering .the combustible mixture, directly'through a suitable duct to thedei sired combustion chamber-' or lire-box. 80

Further objects of'myimpr'ovements are i i .to providev yan apparatus forfeeding and mixing Vcoal-dust `and. the like, whichjgl is positive and'automatic vin its action; '2 has onlyonemoving mechanicaljeleme11t; 5 Y

(3) :may beoperated by a central one hand control@ X4) Afeedsv at different rates -while inaintaining the same proportions`Qfairandl `coal `dust inthel combustible mixture aside-"1 c fte'rmined by =the original adjustment]ofthego apparatus; (5.) iS ISO Compact that 'th apli paratus voccupies onlyfa small'fpartfQfthef` spaceI requ'iredby other feeders, mixers and burners, andfat the same time de livers to the firebox lall the coal and air required-for 95g completel combustion at. all rates'of firing f withoutrequiring admission of additional seeondaryy ain throughv auxiliary ports'.y L

Ajpreferred embodirn'ent v of the apparatus 1 of my'inventiom'and adapted for carryinggm() lo utfltll'e improvedfmethod, is 'illustrated 1n the Iaccornpanyingdrawing forming partV i 1:, p12-inviamifte-impide@ line 2 2.7 Fig. l; andk Y iv-mi- 'Fig 3,.-an end lelevation thereof with portions in section as on line 3- 3, F ig, 2.;

Similar numerals refer to similar parts throughoutthe drawing,

The improved coal dust feeder and mixer indicated generally at l includes a ceal storage bin-2 .preferably having sides slopingV downward at an angle of 60,9 with the 'horizontal and converging tov` a 'preferablyi -large free fromebstructions.""g

This central Openingcommunicates'With' a relatively largel and preferably V cylindric .round central/outlet opening. 423,e.prel:'e1'-`ably I relatively Widefrectangular duct 7WhichQeX-- ten'ds'iand .communicates from the chamber 4 preferably intoV central portions ofA a .'snction inlet 8 .ofa fan 9k of any usual or desiredconstruction, and which may include `fanbladeslOmountedupon a shaft llf'which their@ blades."

The sueengiiete fatte rail 'is preferably vof i a substantially' greaterlcrosssectional area Vthan theareaef the rectangular duct utlet7: froinltheffclosed chamber.

The outlet duct V14k ef4 thefani 'Inunicate .thrugh the 4connecting duct 15 ydirectly toaburner'nozzleynotshwn,which;

` j From the top pf thefoutl may vcommay be located in aQfireLbox.-Lf

Y fana relativelysma-ll V.byjpass pipe lfprefcommunicates from outlet l,duct intev the closed chamber l, through a suitable. aper- Peli-ing@ ,w1 f The Lappetites"iconsnructedes aforesaid,

pulverized fuelasuch as"` coaldusttlQLf Due.

tral outlet yc lpening 5 3, striking '1. thebottom angie engages neturaijengle .ff .he PQSU? Tenet rief the y I claim-Elfe.,

f to ythe relatively steep; slope offthefsidesfof y the bin, the coal dustl falls freely. `dovvn from .thejclsed 'chamberfills up; thefincoming coal v dust naturally .spreadsg and j flows outward "oseandA @ethereal in @hex-eresie .edeeefr0e'-ee lbedi waved level illustrated in Fig. 2, therey being a substantialfree space above the coal Vdust l in `the chamber. yWhen the fan 9 is arted7 therotating blades cause air to flow into the suction in# letB thereof andV out of the outlet duct 14 f i thereof at arat'e vdetermined by the speed of the f an, partof the outlet air of the fan being'by-passedk through thepipe 16 into'the closed chambery 4..

" This V'by-passed' air reaching' the .closed chamber l is of. courseiat'afpre'ssure higher than the suction pressure ofjthesuctioniny, I l'et 8. into'wliich the outlet duct 7 'from the closed chamber extends. Y clese'd Chamber-4,preferably having-a solidV bottom 5 beneath 'the op'ening "andincluding 5. the cylindricsidegvvall 6 in Whichisl-ocated l'prefe'rably a leveLabove the'level of @bin Qoutlet'l pening: .a-g'relatively low and *"The'ihighgpressure air vdelivle'red2, 'i

coalI dust Aintosthe fan suction inletvvherethe@ i coal dust mingleswithtle ingoingfreeair drawn into the suction inlet about'the cham# ber duct outlet'.

, IIn, passingthrough the fanthefcoaldust and air are very thoroughly mixed",afndthis` vcombustblee mixture ."mayl'-:bev out there :being any opportunit for the coal dust to, settle out :of the, mixture),

inthe free space above itsjuppery;

same timelthe lo'W pressure set a 'burnerfthr'ough the Connecting ductfltion'for.the.combustiblemixtureL The quantitybf this unvaryingfmixture 3 110,

of fuel-1 and air'iwhich .delivered into the nre-boX'depends-solely upon the speed of Vable one hand control ofvv thefffan operating Byl properly :proportioning the rel `ative-' ,area; of the closed vchainber'outlet. duct?, the

fan inlet' 8, the relative proportionsof- 'coal *dustgand' air drawn-.into thelfa'n ymaybe A fixed at .a ratio equal;to;t he proper ratio for securingconstantandcomplete combu`serablyV having iafcontrol valve 17 suitably v v mounted at a convenient point inits length,

ratio fof'fuel and yair' the combustible m'iXl ture.

bin,.fa closed chamber, and .a fain, an unobstructed opening from vthe bin communicat- The appaiatusicncein dperatioi'i continiiesi', .i automatically as longA 'asa suitablehead 4of1V meldest A *12'5i 1; A N cembi'ned for -fuel l 4 i i such as coal dust andthe .flike','includingj a Y municating With the fan inlet, the area of N, the fan inlet being different from the area such as coal clust and the like, including a bin, a closed chamber, and a fan, van openingy from the bin communicatingvvith the closedV chamber, the closed chamber having a broad bottom below the opening `and having a` large volume as compared with the rate ofv iioW ofl the Clust fuel Vthrough tliecopening, ancl a duct from the closed chamber oomof the Vduct from the closed chamber.-

B. A Combineclfeeder and mixer forffuel such as coal clust and the'like, including a .'bin, a closedy chamber, and a fan, an opening from the bin communicating with' the closed chamber, the closed chamber having a broad bottom below the opening and having a lar-ge volume as compared with the rate of HOW` ofv the dust fuel through the opening, and a duct romthe closed chamber communicating With the fan inlet, the area ofthe fan vinlet being greater than the area Y of the ductfrom the closed chamber.

4. A combinedrfeeder and mixer for Jfuell such as coal dust and the like, includingv a" bin, a closed chamber, vand a fan, an openclosecl chamber, a duct from. the closed j ing from the bin communicating with the n g n chamber communicating with `the fan' inlet,

and a by-pass communicating fromfthe kfan outlet tothe closel chamber, the end of the by-pass at the closed chamber` being above the opening. 5. A combined feeder-and mixer for `fuel j such as coal `dust and the like, including va bin, va closed chamber, and a fan, an openancl a'by-pass oomrnunicatingfrom the' fan outlet to the closed chambeLthe duct and the end of the by`paiss at the closed chamber i i being above thev opening.

, ing, from the bin communicating with the `closied Chamber, a" duct from-,the closed ohamberfcommunioating Withtlie fan inlet, o

In testimony thatI claimfthe above, I

have hereunto subscribed myname.

` WILLIAM M. BARKER. 

